JP3612815B2 - Tuner device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tuner device such as a satellite broadcast receiving tuner device.
[0002]
[Prior art]
Conventionally, for example, a satellite broadcast receiving tuner device is configured as shown in FIG.
In other words, in FIG. 4, a satellite broadcast receiving tuner device 1 includes an RF tuning amplification unit 3, a mixer 4, an IF amplification unit 5, and an AGC control unit 6 to which a signal from an input terminal 2 to be connected to a BS converter is input. And the FM demodulator 7.
The mixer 4 receives the local oscillation frequency from the oscillator 4a.
Further, a control signal from the AGC control unit 6 is input to the RF tuning amplification unit 3 and the IF amplification unit 5.
[0003]
According to the satellite broadcast receiving tuner device 1 configured as described above, when a signal from the BS converter is input to the RF tuning amplification unit 3, only a desired frequency component passes and is input to the mixer 4. The The mixer 4 receives an oscillation signal having a predetermined local oscillation frequency from the oscillator 4a. The mixer 4 mixes the signal from the RF tuning amplification unit 3 and the oscillation signal to generate an intermediate frequency signal. Is generated.
[0004]
The intermediate frequency signal is amplified by the IF amplifier 5, gain-controlled by the AGC controller 6, and then input to the FM demodulator 7. The FM demodulator 7 demodulates the input signal to output a television signal.
[0005]
Thus, based on this television signal, a video signal is generated by the video processing unit 8 configured separately from the tuner device 1, and an audio signal is generated by the audio processing unit 9. The video signal and the audio signal are inputted to an input terminal of a television device or a video device (not shown) so that they can be displayed on a display device such as a cathode ray tube or recorded on a video tape.
[0006]
[Problems to be solved by the invention]
However, in the satellite broadcast receiving tuner device 1 configured as described above, the video processing unit 8 and the audio processing unit 9 are configured separately from the tuner device 1. Therefore, when assembling the video processing unit 8 and the audio processing unit 9 as one device, there is a problem that the entire device becomes large.
Further, when the tuner device 1 is connected to the video processing unit 8 and the audio processing unit 9, matching adjustment work is required, so that there is a problem that assembly is troublesome. Furthermore, since the audio processing unit 9 generally performs processing by PCM modulation, it has been necessary to put it in a shield case so that noise due to PCM modulation does not leak outside.
[0007]
In view of the above, an object of the present invention is to provide a tuner device that can be configured in a small size and at low cost with a simple configuration and can be easily assembled.
[0008]
[Means for Solving the Problems]
According to the present invention, there is provided a tuner device comprising a sequentially connected RF tuning amplification unit, a mixer unit to which a local oscillation frequency from an oscillator is input, an IF amplification unit, an AGC control unit, and an FM demodulation unit. 2 includes a video processing IC that generates a video signal based on a demodulated signal output from the FM demodulator, and an audio processing IC that generates an audio signal based on the demodulated signal, and is entirely housed in a shield case. The video processing IC and the audio processing IC are separated by the shield case, and the audio crystal oscillator for the audio processing IC clock and the clock for the video processing IC are used. A video crystal oscillator for the video processing IC, and the video crystal oscillator and the audio crystal oscillator are connected to the video processing IC. The tuner device, characterized in that disposed at the position facing Nde is achieved.
[0009]
In the tuner device according to the present invention, preferably, the crystal oscillator for the sound processing unit is formed in the video processing unit.
[0010]
According to the above configuration, since the video processing unit and the audio processing unit for processing the demodulated signal from the FM demodulating unit are configured as an integrated unit, these video processing unit and audio processing unit are connected to the tuner device. There is no need to connect to the output of the FM demodulator. Therefore, connection work and adjustment work are unnecessary, and the tuner device can be easily assembled.
Further, since the voice processing unit is housed in the shield case of the tuner device, noise from the voice processing unit does not leak to the outside.
[0011]
When the crystal oscillator for the audio processing unit is formed in the video processing unit, noise generated from the crystal oscillator does not enter the audio processing unit, so that malfunction of the audio processing unit can be eliminated. Become.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.
1 to 3 show the configuration of an embodiment of a tuner for receiving satellite broadcast according to the present invention.
[0013]
In FIG. 1, a satellite broadcast receiving tuner device 10 includes an RF tuning amplifying unit 12, a mixer 13, an IF amplifying unit 14, an AGC control unit 15 and an FM to which a signal from an input terminal 11 to be connected to a BS converter is input. The demodulator 16 is composed of a video processor 17 and an audio processor 18 arranged in the same unit.
[0014]
Here, the RF tuning amplification unit 12, mixer 13, IF amplification unit 14, AGC control unit 15 and FM demodulation unit 16 are the same as the RF tuning amplification unit 3, mixer 4, IF in the conventional tuner device 1 shown in FIG. The configuration is the same as that of the amplification unit 5, the AGC control unit 6 and the FM demodulation unit 7.
[0015]
As shown in FIG. 1, the video processing unit 17 includes a video processing IC 17a and crystal oscillators 17b and 17c adjacent thereto.
Here, as shown in FIG. 2, the video processing IC 17a includes a de-emphasis low-pass filter 17d, an energy diffusion signal removal circuit 17e, and a video amplification circuit 17f. Based on the demodulated signal from the FM demodulation unit 16, Generate a video signal.
As shown in FIG. 3, the audio processing unit 18 includes an audio processing IC. The audio processing IC includes an audio band-pass filter 18a, a 4-phase DPSK demodulation circuit 18b, and a PCM, as shown in FIG. The demodulating circuit 18c and the analog audio processing circuit 18d are configured to generate an audio signal based on the demodulated signal from the FM peaking section 16.
[0016]
Here, the crystal oscillator 17b is configured to have a vibration frequency of, for example, 18.43 MHz for the clock of the audio processing IC, and the crystal oscillator 17b includes the clock of the video processing IC 17a, the video processing IC 17a, and the audio. For example, the processing IC is configured to have a vibration frequency of 5.72 MHz for the digital filter clock.
[0017]
The satellite broadcast receiving tuner device 10 according to the embodiment of the present invention is configured as described above, and a desired frequency component is obtained by inputting a signal from the BS converter to the RF tuning amplifier 12 from the input terminal 11. Only passes through and is input to the mixer 13. An oscillation signal having a predetermined local oscillation frequency from an oscillator (not shown) is input to the mixer 13, and the mixer 13 mixes the signal from the RF tuning amplification unit 12 and the oscillation signal to obtain an intermediate frequency. Generate a signal.
[0018]
The intermediate frequency signal is amplified by the IF amplification unit 14, gain-controlled by the AGC control unit 15, and then input to the FM demodulation unit 16. The FM demodulator 16 demodulates the input signal to generate a television signal.
[0019]
The television signal is input to the video processing unit 17 and the audio processing unit 18. As a result, the video processing unit 17 generates a video signal, and the audio processing unit 18 generates an audio signal. Thus, the video signal and the audio signal can be displayed on a display device such as a cathode ray tube or recorded on a video tape by being input to an input terminal of a television device or video device (not shown).
[0020]
In this case, since the video processing unit 17 and the audio processing unit 18 are incorporated in the tuner device 10 as an integrated unit, it is necessary to connect the output of the FM demodulation unit 16 to the video processing unit 17 and the audio processing unit 18. Therefore, the matching adjustment work at the time of connection is also unnecessary. Furthermore, the tuner device 10 incorporating the video processing unit 17 and the audio processing unit 18 can be configured to be small as a whole.
[0021]
Further, since the crystal oscillator 17 b used in the audio processing unit 18 is disposed in the video processing unit 17, a filter serving as a noise source is not disposed in the audio processing unit 18. Therefore, the sound processing unit 18 can reduce the influence of noise from the filter.
[0022]
Furthermore, since the PCM demodulation circuit 18c of the audio processing unit 18 is accommodated in the shield case of the tuner device 10, leakage of noise from the audio processing unit 18 to the outside can be reduced.
[0023]
The tuner device 10 may be provided with a BS distributor 19 on the input side. In this case, the BS signal from the input terminal 11 is input to the distributor 19, and one of the two distribution outputs is output to the outside from the output terminal 20, and the other distribution output is RF. Input to the tuning amplifier 12.
As a result, it is possible to distribute the BS signal to other devices such as a television receiver and a video device without the need for an external distributor.
[0024]
【The invention's effect】
As described above, according to the present invention, the video processing unit and the audio processing unit for processing the demodulated signal from the FM demodulation unit are configured as an integrated unit. There is no need to connect the processing unit to the output of the FM demodulation unit of the tuner device. Therefore, connection work and adjustment work are unnecessary, and the tuner device can be easily assembled. Further, since the voice processing unit is housed in the shield case of the tuner device, noise from the voice processing unit does not leak to the outside.
Thus, according to the present invention, it is possible to provide an extremely excellent tuner device that can be configured in a small size and at low cost with a simple configuration and can be easily assembled.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a configuration of an embodiment of a tuner device according to the present invention.
FIG. 2 is a block diagram illustrating a configuration of a video processing unit of the tuner device of FIG. 1;
3 is a block diagram showing a configuration of an audio processing unit of the tuner device of FIG. 1;
FIG. 4 is a block diagram illustrating an example of a conventional tuner device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Tuner apparatus 11 Input terminal 12 RF tuning amplification part 13 Mixer 14 IF amplification part 15 AGC control part 16 FM demodulation part 17 Video processing part 17a Video processing IC
17b, 17b Crystal oscillator 18 Audio processor 19 Distributor 20 Output terminal

Claims (1)

Demodulation output from an FM demodulator in a tuner device comprising a sequentially connected RF tuning amplifier, a mixer that receives a local oscillation frequency from an oscillator, an IF amplifier, an AGC controller, and an FM demodulator A video processing IC for generating a video signal based on the signal and an audio processing IC for generating an audio signal based on the demodulated signal, and the whole is housed in a shield case and configured as an integral unit ; The video processing IC and the audio processing IC are separated by the shield case, and an audio crystal oscillator for the audio processing IC clock and a video crystal oscillator for the video processing IC clock are connected to the video processing IC. The crystal oscillator for video and the crystal oscillator for audio are arranged in a position facing each other across the video processing IC. Tuner and wherein the door.

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